public class Numbers 
{
   /**
      Produces a string containing the numbers in an array,
      separated by commas, such as "1,4,9"
      @param values an array of integer values
      @return a string containing the array elements, separated by
      commas.
    */
   public String separateWithCommas(int[] values)
   {
      // your work here
      int l=values.length;
      String s="";
      for(int i=0;i<l-1;i++){
         s+=values[i]+",";
      }
      s+=values[l-1];
      return s;
   }
}